Dual flash welding apparatus



April 7, 1942. JENS 2,278,615

DUAL FLASH WELDING APPARATUS Filad Nov. 22, 1940 v 3 Sheets-Sheet 1 Inventor-z fflber-t K. Jens.

Kttorneg! April 7, 1942. A. A. JEN'S 2,

DUAL FLASH WELDING APPARATUS Filed No v. 22, 1940 5 sheetsfsheet 2 La P35 lbebt ens Kt'tOiZGH Irive nio r:

April 9 A. A. JENS 2,278,615

DUAL FLASH WELDING APPARATUS Filed Nov. 22, 1940 3 s ;s t 5 26 Fig-6 F1357 I. ffiber-t fCU'ens.

Ettor- 65 Inventor:

Patented Apr. 7, 1942 UNITED'STATES PATENT OFFICE DUAL FLASH WELDING APPARATUS Albert A. Jens, St. Paul, Minn. Application November 22, 1940, Serial No. 366,568

3 Claims.

My invention relates to dual flash-welding apparatus, and has for its object to provide a machine having a current supply and a transformer for delivering a large volume of secondary or welding current together with dual work-holding means, means for supplying the welding current to work held in either of the work-holding means alternatively and not to both at the same time, and means for independently regulating the volume of current to either of said work-holding means.

In connection with what is known as flash welding or arc welding the means for delivering current through the transformer and to the work to be welded is very expensive and exacting, requiring costly and precise forms of apparatus including large conductor areas to obtain suitably eflicient results. Yet this complex and costly apparatus in common practice is out of operation much of the time, because following every welding operation it is necessary to remove the welded work and to set up new work for welding purposes, which necessarily consumes much time.

I have discovered that this wasteful procedure may be avoided by providing dual work-holding means in combination with a single current supply together with means for shifting the current from one to the other of these work-holding means and vice versa.

It is a principal object of my invention, therefore, to provide a single source of supply of suitable welding current in association with dual means for holding work, together with means for delivering the welding current to one or the other of said working-holding instrumentalities and including current shifting means which simultaneously cuts off current from one of the work-holding means and causes its delivery to the other work-holding means.

It frequently may happen that the volume of current which will be used on work of one of the work-holding means may be greater or less than the volume of current required for work in the other work-holding means. To meet this difilculty it is an object of my invention to provide independentcurrent control means for regulat ing the volume of current fed to the respective work-holding means so that the volume may be made great or small for either of them without reference to the volume going. to the other workholding means.

It is a further object of my invention to provide a current shifting means which will, in combination with a single centrally located lever readily accessible from both sides of the machine,

at the same time shift the welding current from one work-holding means to another and disconnect the current regulating means from one side and connecting it to the other side.

The full objects and advantages of my invention will appear in connection with the detailed description hereinafter to be given, and the novel features of the invention by which the aforesaid advantageous results are obtained are particularly pointed out in the claims.

In the drawings illustrating an application of my invention in-one form:

Fig. 1 is a plan view of the entire apparatus with some parts broken away and in section.

Fig. 2 is an end elevation view with some parts in section.

Fig. 3 is a sectional view taken on line 3-3 of As illustrated a frame I0 is supported bylegs II and has thereon a table l2. Upon the table I2 is mounted two pairs of work-holding blocks l3 and I 5, and I4 and I6, respectively. The respective pairs of blocks are located on opposite sides of table 12 in alinement and are separated by spaces I1 and I1 respectively.-

The particular work illustrated in the drawings is the welding of well points and fittings on lengths of pipe for which reason the block I4 is provided with a semi-cylindrical seat I8, Fig. 2, and the block l3 with'a semi-conical seat l9, Fig. 1. i

In each instance the work-holding vise is completed by swinging blocks 20 and 2|, Fig.2, which are connected by toggle links 22 and 23 with the short arms 24 and25 of levers 26 and'2l. The blocks 20 and 2| are formed with hemispherical seats 28 and 29 shaped to receive the work and are provided with insulation as indicated at 30 and 3| of Fig. 2 of the drawings. The manner of using this vise arrangement is best illustrated at the right of Fig. 2 where the lever 26 is shown pivoted at 34 and the block 20 is shown pivoted at 35. It will be obvious from this arrangement that .by swinging the lever 28 to the dotted line position of Fig. 2 the block 20 will be swung away to leave access to the work rest seat I8. Work then resting upon the seat I8 may be withdrawn and new work put in its place, after which the lever 28 will be swung back to its erect position whereby the seat 28 will be caused to engage the work with a strong clamping action to hold it firmly in position during the welding operation.

Bottom blocks I3, I4, I5 and I8 are, as shown in detail in Fig. 2, supported by a series of platen bases 38, 31, 38 and 39 all mounted to slide in ways such as indicated at 40 and 4! of Fig. 2, the sliding platens being insulated from the bottom supporting blocks, as indicated at 42 of Fig. 2. The other parts of the four vises shown, including the upper blocks 20 and 2I and the levers and connecting mechanisms 28 and 21, are all mounted on the platens 38, 31, 38 and 39 respectively and move with these platens. The specific vises or work-holding mechanisms on each platen are of the same nature and are mounted and of course is necessarily at all times in circuit with the secondary or welding current induced by the primary current through the transformer.

The contact plate 88 has thereon a head plate 94 and the contact piece 81 has thereon a head plate 95. To the head plate 94 is secured a conductor 98 formed of a multiplicity of flexible copper strips and similarly to the head plate 95 is secured a similarly formed conductor 91. Conductor 88 is bolted to the head 98 of a T-piece which has its shank I secured by bolt 38 to ears and operate in the same way, though of course they may be shaped diiferently in any instance so as to hold different types of work.

In assembling the work in practice, in the ex ample shown, the fitting end 41 is first put in vise block I4 and the pipe section 48 is' put in vise block I8 and spaced therefrom as indicated at 49 a suitable distance which may be determined by a gage plate for that purpose. The work is then looked in position by operation of the vise levers 28 and is ready for welding. On the other side, in the example shown, the well point 80 is inserted in block I3, pipe Si is inserted in block I and the securing and spacing effected in the same manner. 1

Upon the transformer terminal 43 extending through the top plate I2 and insulated therefrom is secured by means of bolts 44 two sets of large copper leaf conductors 45 and 48. Bent as shown and in turn secured by bolts 82 and 83 to heads 84 and 85 of T-arms which have their shanks 81 and 88 held between respective pairs of ears 89 and 1| and and 12. The conductors 48 are thus put in circuit with the work-holder mechanisms supported by platens 38 and 31. But this connection of conductors leaves the platen free for sliding movements later to be described because of the flexibility of the curved portions of conductor strips 45 and 48.

Referring to Figs. 1, 2 and 3, a bracket plate 13 is secured to and forms a part of the pole piece of the transformer 90. This bracket plate is provided with a part circular standard 14 and has outwardly extending internally threaded bosses and 18 therethrough which coact with a thread 18 on a shaft 19. Fast on shaft 19 are a pair of circular header plates 80 and BI, Fig. 3, secured in position by sets of nuts 82 and 83. Secured to the header plates 80 and BI but insulated therefrom, as indicated at 84 and 85 are a pair of contact plates 88 and 81. These plates are provided with cylindrical depressions 88 and 89 which surround the bosses 15 and 18 but are spaced therefrom and also are spaced from the shaft 19 so that at all times the shaft 19 and the end blocks 84 and 85 secured thereto are insulated from the central standard 14, which, as will be later pointed out, is normally in circuit with the secondary current induced in the transformer designated generally by the reference character 90 onFig. 2. The pole piece 9I of this transformer forms a direct support for the plate 13 which extends through an opening 92, Fig. 2, in the top plate I2,

I02 and I04 fast on a block I08. Similarly the conductor 91 is bolted to the head 99 of a T- piece whose shank IOI extends between ears I03 and I05 fast on a block I01. It follows from the above arrangement that the contact pieces 88 and 81 both fasten the shaft 19 may be simultaneously shifted and the flexibility of the conductors 98 and 91 will permit such shifting. It also will be apparent from Figs. 1 and 3 that the conductor standard 14 may be contacted either with the contact plate 88 or the contact plate 81. As shown in these figures contact plate 81 is in contact with the conductor standard 14 and contact plate 88 is spaced as indicated at I08 from the conductor 14.

The shifting of the contact plates from one position to the other is effected by means of a hand lever I09 on a hub IIO pinned to the shaft 19 and supported in a bearing on a standard I l i, Fig. 1, which in turn is supported on top plate I2. Pinned on shaft 19 is also the hub II2 of a lever arm H3 which is connected by a link II4 with an arm H5 fast on an insulating block H8, Figs. 2 and 7, which carries a series of switch contacting arms H1 H8, and H9 which are severally pivoted to standards I20, I21 and I22 depending from a switch block I23 carried by a frame extension I24, Figs. 1, 2 and '1.

As shown in Fig. 7, the contact arms I I1, H8 and I I9 are in conducting engagement with switch posts I25, I28 and I21 whereby a regulated volume of current by operation of the switch causes conducting connections to be effected for delivering a regulated amount of current to the transformer for effecting a regulated flow of sec* ondary or welding current to one of the workholding means. i

A second set of contact posts I28, I29 and III is adapted to be engaged by switch contact arms H1, III! and H9 when the handle I09 is thrown to its opposite position, as appears very clearly from Figs. 2 and 1. Swinging the handle in that manner will rotate the worm or thread 18 on shaft 19 within the threaded opening 11 with the result that contact blocks 88 and 81 are simultaneously moved to take contact block 81 out of contact with the conducting standard 14 and bring the face of contact block 88 into engagement with said central conducting block, the movement being such as to close the gap I3I, Fig. 3, between the faces of contact block 88 and standard 14.

Thus the swinging of the lever I09 from the position of Fig. 2 to its maximum position in the other direction will simultaneously shift contact of the induced secondary or welding circuit from the work-holding means at the left of Fig. 2 to the work-holding means at the right of Fig. 2, and shift the contacts for line control from contact posts I25, I28 and I21 to contact posts I28, I29 and I30 for a purpose and effecting a result as now will be described.

Referring to the wiring diagram of Fig. 1,

main welding current, ordinarily 440 volt line current, is delivered from line wires I3I and I32. As shown, wire I 3I goes through a switch box I39 where itis normally broken by separated contacts I34, I35 adaptedto be closed by a contact piece I35 on a relay I31 operated as follows:

he relay is fed by a second line wire I36 preferably carrying 220 volts, the other, or return wire, being designated as I39. From the relay I31 a wire I40 goes through a branch wire I to a normally open switch I42 which is closed and held closed for a suitable period of time by a cam I43, as will be later described. From switch I42 goes a wire I44 which leads to switch block I21 so that with the switch in the position of Fig. 7 the current returns from supporting post I22 through outlet line I39. It follows that with the parts in the position of Fig. 7, whenever switch I42 is closed current passes through relay I31 which closes the contacts I35 and I34 permitting welding current to pass to the transformer as hereinafter described.

Wire I40 also through a branch wire I45 goes to a second switch I46 operated by a second cam I41. Cam. I43 is associated with one of the workholding means and cam I41 with the other workholding means. When cam I41 is operated to close switch I46 current goes through wire I 48 to block I30, and from there when the switch is shifted from the position of Figs. 2 and 7 to make contact with switch I30 through the arm H9 and support I22 to return line wire I39.

Not only are the cam members I43 and I41 adapted to contact the various contacts I66, I 61, I66, I59, I10 and IN. A wire I16 leads. from the arm I12 to contact post I25. Similarly'a wire I11 leads from the arm I14 to a contact post I26.

It follows that with the parts in the position indicated in the diagram of Fig. 7 the welding circuit through the transformer I53 is closed from. lead-in wire I49 through standard I 2I, switch arm IIO, contact post I26, branch wire I50, wire I52 through the transformer thence through wire I51 to contact I62, through contact arm I12 and wire I16 to contact post I and through standard I20 back to a wire I16 to the line wire I32.

As shown, if switch H5 is put in reverse position the current will gofrom contact post I29 through branch wire I'5I, wire I52 through the transformer I53, through wire I56, contact I 61, contact arm I14 and through wire I11 to contact post I26, thence through switch arm H1 and standard I20 through wire I16 back to the line wire I32.

The purpose of this switching arrangement is to provide suitable variations of current volume for the different work-holders so that work requiring large volume of current may be properly handled and welded on one of these work-hold- I ers and at the same time, by the mere shift of independently operative inconjunction with the independent operation of the two sets of workholding means heretofore described, but only one of said cam-operating means can be effective for passing current when the switch member II5 has been operated to put into circuit the parts for the corresponding work-holding means. Thatis, cam I43 can operate to pass current when switch H5 is in the position of Figs. 7 and 2 but not when it is in the opposite position. Similarly cam I41 cannot operate to pass current (because of the break between I22 and I30 when the parts are in the position of Figs. 2 and 7), but can become operative when, by manipulation of handle I09, the parts are shifted to make switching contact with contact posts I26, I29 and I30.

Also it will be apparent that when cam I43 or I41 has traveled through a part of a revolution it will first close either switch I42 or' switch I46 and then permit their automatic reopening to terminate the flow of current to the work in the work-holder which has been selected. The main welding current going to the transformer also is controlled by the switch II5. This current goes by wire I49 to the standard or supporting post I2I from which it may pass through switch arm II6 either to contact post I25, as shown in the diagram of Fig. 7 and in Fig. 2, or to contact post I29. A branch wire I50 from contact post I26 and a branch wire I5I from contact post I29 goesv to a main feed wire I52leadi'ng .to the transformer indicated diagrammatically at I53.

From the transformer I53 lead a series of wires I54, I55, I56, I61, I56 and I59. These several wires have sets of branch wires, as shown in Fig. 7, leading to two sets of contacts I60, I6I, I62, I63, I64 and I65; and I66, I61, I66, I69, I10 and HI respectively. A contact finger I12 is on a shaft I13 and coacts with the various contacts I60, I6I, I62, I63, I64 and I65. Asimilar contact finger I14 is on a shaft I15 and is the switches, work requiring a relatively low volume of current may be done on the other workholding device. .The rheostat contact arms I12 and I14 on shafts I13 and I15 respectively are,

operatedby knobs I60 and I6I, Figs. 1 and 5. An indicator needle I62 moves over a dial I63, Fig. 5, in a housing I64 (or I65), the dial having thereon indications for .the various contacts I60 to I65 in one rheostat andthe contacts I66 to I1I of the other rheostat.

By this means the volume of current supplied to the transformer is determined in advance by the position of contact arms I12 and I14, and the volume of current delivered to the .transformer will be regulated and determined thereby and will be transmitted in variable amounts according .to the particular work-holding means that may be switched into operation.

The secondary or welding current from transformer I53 may go through either of two circuits as may be desired. In the wiring diagram the circuit closed by contact piece 61 with a surface of contact standard 14 goes through a wire I66 to work-holding block I01 with work 46 therein. The current will be caused to move across gap 49 by means hereinafter described to work 41 in holding block I4 from which the secondary or .welding current returns through wire I61.

The other circuit includes the contact piece 66 and a wire Ill which goes to the work-holding block I06 having therein work 6| and across a gap there indicated at I69 to work 60 in holding block I3 and thence through return wire I90.

It will be apparent from the above, that after the ..volumes of current have been fixed for the respective work-holding means by manipulation of knobs I60 and I II, the current so determined in volume goes to the transformer I53, and the resultingsecondary, current induced through the sition at the other side of the center of the machine.

Thus, as indicated in Fig. 1, welding has been completed on the work 80, BI, and the lever I09 has been swung to its other. side position causing at the same time contact plate 83 to engage the side surface of contact 14 and causing the switch II to shift from the contact posts I28, I29 and I30 to the contact posts I25, I26 and I21, thus causing the selected volume of current when switch I42 is closed to pass to the transformer and effect the welding operation on the work 41 and 48. The reverse operation will be effected by the swinging of handle I09 in the opposite direction through its maximum extent of swing.

The welding operation itself for either of the work-holding means is as follows: Referring to Fig. 6 the slide 39 carrying the work-holding blocks I4 and 20 and one part of the work 41 has secured thereto by means of screws I9 I a top arm I92. This top arm carries a pair of rollers I93 and I94, Figs. 1 and 6, which at all times engage a cam I95 of a shape most clearly outlined in Figs. 1 and 4.

Since these parts are identically the same on the two sides of the machine, the same reference numerals are applied to each of them. A spur gear I96 is on a shaft I91 which carries an operating handle I99 on a hub I99 keyed to shaft I91. The spur gear I96 meshes with a gear 200 on a shaft 20I, Figs. 1 and 6. A supporting hub 202 rides in a depression 203 in the top plate I2. The shaft MI is keyed to the cam member I95 above the support 202 and an extension 204 of shaft 20I has keyed thereto the switch controlling cam member I43.

The above description applies equally well for both sets of work-holding means, a second crank handle 205 being positioned to operate the second work-holding means indicated by blocks I3 and I00.

Having reference to Fig. 1, upper right, and Fig. 4, it will be seen that the cam I95 has its edge surface, in the main, eccentric to the shaft 20I. part of cam edge surface indicated at 209 engageable with roller I93 is at the maximum dis tance from the center of shaft 20I while the opposite portion 201 engageable with roller I94 is at the minimum distance from the center of shaft 20I. In this position the slide 3a (or 3'!) is drawn away from slide 38 (or slide 39) the maximum distance to leave the gap 9 between portions 41 and 43 of the work, which gap has been determined by means of a suitable gage plate.

The high point 206 of the cam is followed by a depression 209 at one side of the cam with a corresponding elevation 209 at the other side of the cam. Following the depression 208 is a further raised portion 2I0 of the cam edge and an extended portion 2!! gradually approaching closer to the center of the shaft 20I, and following the raised portion 209 is a corresponding depressed portion 2l2 followed by an elongated portion 2I3 which gradually extends farther and farther from the center of shaft 20I.

Also as shown in Fig. 4 as well as Fig. 6, the switch operating cam I43 (or I41) is'fast on shaft 204, a continuation of and revolvable with shaft 20I. This cam and the cam I95 are shown in Figs. 1 and 4 in the set-up position, that is, the position when the work is put in the workholders and the machine is not operating. As shown, these cams may be turned by hand by Also that as shown in Figs. 1 and 2, the

either the crank I99 or the crank 205, although obviously automatic means may be employed for turning them. The operation in turning the shaft 20I for either set of cams will be as follows:

First, simultaneously the slide 39 (or 31) will be caused to move forward to close the gap 49 between the parts of the work held on the workllolder and the cam I43 will close the appropriate switch so as to send primary current to the transformer and induce secondary or welding current through the particular welding circuit in which it is connected. This will result in the start of welding action. Continued movement of the cam I95 will then first cause the parts of the work to separate slightly and then cause them to approach each other through the major part of a half turn, thus taking care of burnoff at the ends of the work and providing the necessary period of delivery of'welding current through operation of the cam I43 on a roller 2 carried by a lever 2I5 which is on the switch operating shaft 2 I 6.

When the pieces of work are caused to approach each other the slide 38 may be pushed backward against the force of springs 2I1, 2I9, Fig. 1, and similarly the slide 39 may be pushed back against the force of springs 2I9, 220. As is clearly indicated in Fig. 4, the cam I43 acts to turn off the welding current before the half-turn of cam I95 is completed so that welding is complete at the first half-turn.

As clearly indicated in Fig. 1, there is a twotoone gear ratio between pinion I96 and spur gear 200. Hence one complete turn of crank I or crank 205 rotates the cam I through a half revolution. A second complete turn will restore the parts to the operative position of Figs. 1 and 4. This second turn to bring the parts back to initial position ready to be operated again will ordinarily be made after the work has been released from the vise.

The advantages of my invention will sufficiently appear from the foregoing description. A simple and effective arrangement of parts and control of current enables a single source of electrical current to act on a single transformer to induce secondary 01' welding current, which in turn may be transmitted to either of two workholding'means. At the same time the volume of current for each works-holding means may be set independently for desired variations, and the operation of a single lever will shift from one to the other oi said wor -holding means, always with the respective c1 nit volume as set.

This actually doub he "ating efilciency of the welding apparatus as a Whole, for always time must be consumed in to log out finished work and in setting up new work. For the apparatus of my invention this is not lost time, because while removal and set-up is taking place on1 one side welding is being effected on the other s1 e.

I claim:

1. A duel flash-welding apparatus, comprising a source of primary current, a transformer to which said primary current fed and by which a secondary or welding current is generated, a plurality of independent circuits for said welding current, an independent work-holding vise with means for holding the work to be welded in each of said circuits, separate means for each of said independent circuits for controlling the volume of primary current going to the transformer, and means for simultaneously breaking one of said circuits and closing the other and for shifting the primary current from passing through one of said volume regulating means andcausing it to pass through the other-volume regulating means.

2. A dual flash-welding apparatus, comprising a source of primary current, a transformer to which said primary current is fed, and by which a secondary or welding current is induced, a plurality of independent circuits for said welding current, an independent work-holding vise with means for holding the work to be welded in each of saidcircuits, separate means for each of said independent circuits for controlling the a source of primary current, a transformer to which said primary current is fed and by which a secondary or welding current is induced, a plurality of independent circuits for said welding current, an independent work-holding vise with means for holding the work to be welded in each of said circuits, separate means for each of said independent circuits for controlling the volume of primary current, a second source of current connections therefrom for throwing in the main primary current to go to the transformer through one or the other of said volumecontrolling means, independent switching means operative for each of said independent circuits for switching on and ofi said second source of current, and means operated in conjunction with operation of the work-holding means during welding for automatically operating said lastnamed switching means.

' ALBERT A. JENS. 

